﻿Ixxxii PEOCEEI)I^'GS OF THE GEOLOGICAL SOCIETY. [^ay I908, 



admitted that this substance was formed from ancient vegetation, 

 and even by those who connected it with the abundant plant- 

 remains in the associated strata, it was commonly looked upon as so 

 much drifted vegetation which was washed off the land and buried 

 under sand and mud on the neighbouring sea-floor. The reiterated 

 devastations of successive seasons were supposed to have produced 

 the repetition and alternation of coal-seams with the sandstones 

 and shales among which they are intercalated. Towards the 

 solution of this interesting question one of the first steps was 

 obviously the careful study of tbe structure and relations of all the 

 coal-bearing strata. The first observer who made this detailed 

 examination was a Pellow of this Society, W. E. Logan, who found 

 that in the South Wales coal-field the seams of coal rest upon an 

 underclay through which Stigmci'ri a-voots freely branch, and which, 

 in his opinion, represents the soil whereon the vegetation actually 

 grew that has been changed into coal. Although this observation 

 might not be applicable to every coal-field or to every seam in any 

 single coal-field, its importance was at once recognized, and it has 

 infiuenced all the subsequent discussion of the subject.^ 



Of the numerous papers on the stratigraphy of the Carboniferous 

 formations which have been printed in our publications, the earliest 

 and by no means the least valuable was N. J. Winch's description 

 of these rocks as developed in jSTorthumberland and Durham, which 

 was read to the Society in 1814, and is contained in the fourth 

 volume of the Transactions. Availing himself of the copious inform- 

 ation supplied by mining records, the author was enabled to present 

 the first detailed account of the successive subdivisions of one of 

 our great mineral-fields. Another early and valuable memoir was 

 that by Buckland & Conybeare on the south-western coal- district of 

 England, which was published in the Transactions for 1824. The 

 Coalbrookdale coal-field was the subject of Prestwich's well-known 

 essay, which was printed in the fifth volume of the second series of 

 the Transactions (1840). In more recent years the detailed study 

 of our coal-fields has been, for the most part, undertaken by the 

 Geological Survey, and the results have been given in a series of 

 official memoirs. But a few papers of considerable interest and 

 importance have appeared in our Quarterly Journal. I may parti- 

 cularly refer to Mr. Cantrill's account of the coal-field of Wyre 

 Forest, wherein he strongly supported the view, which had been 



1 The paper in which it was recorded appeared in the sixth yolume of th& 

 second series of Transactions, published in 1841. 



